﻿using System;
using System.Security.Cryptography;  
using System.Text;

public class DESEncrypt
{
    /// <summary>
    /// DES加密/解密类. 
    /// Copyright (C) Maticsoft
    /// </summary>
    public DESEncrypt()
    {
    }

    #region ========加密========

    /// <summary>
    /// 加密
    /// </summary>
    /// <param name="Text"></param>
    /// <returns></returns>
    public static string Encrypt(string Text)
    {
        return Encrypt(Text, "28LH48");
    }
    /// <summary> 
    /// 加密数据 
    /// </summary> 
    /// <param name="Text"></param> 
    /// <param name="sKey"></param> 
    /// <returns></returns> 
    public static string Encrypt(string Text, string sKey)
    {
        DESCryptoServiceProvider des = new DESCryptoServiceProvider();
        byte[] inputByteArray;
        inputByteArray = Encoding.Default.GetBytes(Text);
        des.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
        des.IV = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
        System.IO.MemoryStream ms = new System.IO.MemoryStream();
        CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
        cs.Write(inputByteArray, 0, inputByteArray.Length);
        cs.FlushFinalBlock();
        StringBuilder ret = new StringBuilder();
        foreach (byte b in ms.ToArray())
        {
            ret.AppendFormat("{0:X2}", b);
        }
        return ret.ToString();
    }

    #endregion

    #region ========解密========


    /// <summary>
    /// 解密
    /// </summary>
    /// <param name="Text"></param>
    /// <returns></returns>
    public static string Decrypt(string Text)
    {
        return Decrypt(Text, "28LH48");
    }
    /// <summary> 
    /// 解密数据 
    /// </summary> 
    /// <param name="Text"></param> 
    /// <param name="sKey"></param> 
    /// <returns></returns> 
    public static string Decrypt(string Text, string sKey)
    {
        DESCryptoServiceProvider des = new DESCryptoServiceProvider();
        int len;
        len = Text.Length / 2;
        byte[] inputByteArray = new byte[len];
        int x, i;
        for (x = 0; x < len; x++)
        {
            i = Convert.ToInt32(Text.Substring(x * 2, 2), 16);
            inputByteArray[x] = (byte)i;
        }
        des.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
        des.IV = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey, "md5").Substring(0, 8));
        System.IO.MemoryStream ms = new System.IO.MemoryStream();
        CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
        cs.Write(inputByteArray, 0, inputByteArray.Length);
        cs.FlushFinalBlock();
        return Encoding.Default.GetString(ms.ToArray());
    }

    #endregion
}
